Ongoing starter/starting issues

Rooster

Rooster

piccole ma cattive
Hey folks, this has been going on since I bought the car over 5 years ago. Intermittently, especially when its been sitting, I try to turn the car over and nothing happens. Let me explain. Key to on - pump initiates, everything "normal". key to start - huge power sag, no solenoid engagement, no starter motor turning over. If I "rap" on the starter or transmission housing, it may kick over. Usually I have to pull the starter every season for the first time. I've had the starter tested numerous times, everybody says its fine, I think its a grounding issue.

Car - 1982 1500FI, turbo charged.
BWM - Unknown
 
2 problems

I will tell you what I have found over the years.

First of if you dont hear a click then there is a wiring problem, bad ground maybe, but the push on connector on the starter may not be making a good contact.

If you hear just a click and nothing, still can be the ground but what I have found is it normally the solenoid contacts at the end of the solenoid plundger. Bench testing proves nothing as the starter is not loaded. When I state loaded I am refering to what the solenoid does. It moves the starter pinion into mesh with the ring gear on the flywheel. And only when the mesh is fully engaged does the plundger contact make to drive the starter. The pinion has a bevel on it, its purpose is to engaged the ring gear even if it is out of mesh, it literally drives a wedge to bring the two gears into mesh. The plundger contact takes the full load of the starter and over time it burns away. Hot starting can be more of a problem as it requires more power to turn a hot engine and bring it into mesh than a cold one.

Replace the solenoid and your troubles will be gone for another 10 years.

TonyK.

Grimsby Ontario Canada.
 
Not sure this is helpful...

I think it's likely corroded or carboned contacts in the solenoid, as mentioned, or a "dead spot" on the armature. Bench testing is notorious for glossing over such defects.

If you really think grounding is an issue, replace the chassis-engine ground (or add another). A nice fat 4g wire does the trick.

Also, in VW circles, this condition is referred to the "Bosch Blues" meaning it's a common enough malady to warrant a cute nickname. The "fix" is to put a 40A relay in the solenoid circuit, so that the ignition switch circuitry doesn't affect the amount of current getting to the solenoid.

One question; you said the pump cycles when the key is turned to "on", is this a mod you've done? Normally the L-Jet system only runs the pump during start or if the AFM flap is open, just wondering.

Hope this helps!:hug:
 
Mike... easiest first...

1. Take a jumper cable and connect it to the engine block and find a good spot on the chassis for the other end. Now you have a temporary ADDITIONAL GROUND STRAP!

Try to start it again. If it works, then the ground issue was the problem. if it remains the same, then the problem is elsewhere.

2. Next... prove the ignition switch. Take a long "test lead" from the + post of the battery and touch it to the RED wire on either the ignition switch or the connector to the ignition switch. If the starter fails to turn and acts the same... then the problem is in the wiring or the solenoid as Tony K stated. If it turns over, then the problem is in the ignition switch.

To prove the wiring back to the starter is OK or not... take the test lead and run it all the way to the terminal on the starter where the RED lead connects to. Be careful... terminate it at the starter first, then touch it to the battery. If it fails, then the problem is indeed internal to the solenoid or the starter. (I'm assuming the + Cable is in good shape and tight!!!)

Rebuilding or replacing the iginiton switch... (I believe Greg Smith did a write up on this) or add a NEW start button, ala BMW and others (like Rudy did a while back)...

HTH...
 
Thanks guys, I appreciate the responses so far!

Also, I plan on installing a 4awg ground loop from one of the starter bolts, to the trans ground point to the frame as I'm a big fan of direct connection...
 
Mike,

As you describe a "huge power sag" when you turn the key, I suspect a ground issue is not your problem... current is going somewhere. It sounds more like a starter/seleniod issue to me. Some years ago I had a VW with a similar intermitant problem... starter bench tested fine, but I decided to replace it anyway. Fixed the problem...
 
Hmmm, I'll have to see if I have another starter around somewhere.

Quick question, are the starters generally split up between Carb and FI, or 1300 and 1500? I know my 1.3 Uno is different.
 
1300 vs 1500

Hi Mike,

The starters were for the 1300 or the 1500. Fueling style did not matter. The difference has to do with the flywheel size IIRC.
 
Welp... if I may suggest...

The starter bolted to to the block in three places is a pretty damn good GROUND connection as is. Its grounding the block to the chassis that is the primary issue.

The Fiat engineers thought it might be best to run a strap from the trans to the chassis down below in the MUCK AND MIRE so as to enhance its chances for corrosion and give their in-laws in the towing a business an income for life!

I suggest you run the second strap up on top, in the relatively dry and warm area from like the cam cover to a body bolt on the firewall... where its easy to see, service and easily check for snugness.
 
What Tony said...

About the starter grounding (to the block) is very true. That furry braided ground strap from the transmission is something you should be looking to replace. (over running another ground from the starter.)

Something not mentioned:
The spade connection that connects to your solenoid is something you should suspect. It's got a factory installed heat-shrink covering on it, but still, the connection in that terminal is usually suspect. We can check it out, maybe replace it with something new.

Mike, make your life easy and bring that car over so I can help you fix it once and for all. We'll nail that problem down and give yer tap hammer a permanent break! :dead:

BTW, I'm looking at getting the scrap X in 3 weeks or less, so prepare for a bit of harness recovery (and other) work. Sound OK?

Also, I'm in Chicago today and tomorrow. :dance2:
 
bbrown said:
About the starter grounding (to the block) is very true. That furry braided ground strap from the transmission is something you should be looking to replace. (over running another ground from the starter.)

Something not mentioned:
The spade connection that connects to your solenoid is something you should suspect. It's got a factory installed heat-shrink covering on it, but still, the connection in that terminal is usually suspect. We can check it out, maybe replace it with something new.

Mike, make your life easy and bring that car over so I can help you fix it once and for all. We'll nail that problem down and give yer tap hammer a permanent break! :dead:

BTW, I'm looking at getting the scrap X in 3 weeks or less, so prepare for a bit of harness recovery (and other) work. Sound OK?

Also, I'm in Chicago today and tomorrow. :dance2:
Click to expand...

I'm thinking we should just get the car over to your place and gut the old wiring harness and install the new! With a few mods of course...
 
why not direct to battery?

What about a direct ground, maybe add to where the ground cable from the battery bolts to the front firewall. From there through the tunnel directly to the motor, securing with one of the starter bolts.
 
The weird thing about our starters

Much of the usual advice about starters won't work for our cars because the starter motor coil is part of the solenoid circuit.

I'm guessing (as TonyK and Greg suggest) that you're not getting good contact inside the starter solenoid.

The solenoid coil completes a circuit from the start switch through the motor coil to ground; so it doesn't work to try to bypass it with an external relay -if you do, the starter motor will spin but the solenoid won't fire.
The symptoms you describe would suggest that the solenoid is firing but not making contact -so you're seeing heavy current draw through the solenoid/coil circuit; but if the contacts don't close, the starter motor won't turn.

You'll need to take the solenoid apart, and you will more than likely find the contacts worn away. It's also common to find a lot of carbon dust in there. If there's enough of it, it will also cause problems getting enough current to the starter.
 
Ha! I got it started and all it needed was a good battery charge! Seems likely that my starter is a little temperamental about having close to optimal voltage. I'll get a starter rebuilt soon and swap it out.

Thanks for all of the suggestions folks!
 
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